The Scariest Game you have ever played

So I was wondering what the scariest game that people here at Gamespot have played.

I'm kinda new to the horror genre so i have only played Resident Evil Deadly Silence and Resident Evil 4. Resident Evil Deadly Silence is not that scary to me but Resident Evil 4 scares the crap out of me sometimes.

So whats your opinions on the scariest game you have ever played.

Half-Life was scary for me. Having those little monsters attacking you from nowhere and jumping right in front of the screen scared the crap out of me.